It is becoming increasingly popular to discuss and address issues such as caring for the environment, global warming, and pollution control. Concerns about global warming and greenhouse gases have led to efforts that encourage reduction of carbon emissions, allocate carbon emissions credits, monitor carbon emissions, and trade carbon emission credits in a manner akin to commodities or utilities (such as water and electrical power). Emission credits, such as verified emissions reduction (VER) credits, represent a quantity of a substance such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), or other greenhouse gas that is commonly emitted by industrial plants, agricultural activities, aircraft, and vehicles. A number of organizations (such as the non-profit Carbonfund.org Foundation) enable consumers to offset their carbon emissions by purchasing or trading emission credits. For example, if a passenger on a commercial airline flight wishes to offset the amount of greenhouse gas emitted into the atmosphere as a result of her flight, she can purchase an equivalent amount of emission credits, where the money spent to purchase the emission credits is used to fund systems, processes, and programs that are intended to reduce the emission of greenhouse gases. In theory, the money spent to purchase the emission credits results in a reduction of emitted greenhouse gases that offsets the amount of greenhouse gases actually emitted by the aircraft (as prorated to account for the individual contribution of the purchaser). The website maintained by the Carbonfund.org Foundation provides additional information about carbon footprints, carbon offsets, and how people can help to reduce carbon-based emissions.
Some organizations provide a service that allows consumers to offset carbon emissions associated with vehicle usage. One such service is offered by AgCert International PLC through its Driving Green website (www.drivinggreen.com). This online service allows a user to estimate the annual amount of greenhouse gases emitted by a vehicle, based upon the following user-entered data: the vehicle manufacturer, the model, the model year, and the annual driving distance for a vehicle. The online service generates a rough estimate of the total weight of greenhouse gases produced by the designated vehicle during the course of one year, and gives the user the option to purchase emission credits to offset the estimated amount of greenhouse gases. This model relies on an honor system in that the user is free to enter any data for calculation of the estimated amount of greenhouse gases. In addition, this system does not facilitate real-time and accurate monitoring and tracking of the actual amount of carbon dioxide generated by a vehicle during operation.